Definitions
The following definitions are employed throughout the detail discussion:
activating station—the DTE, DCE and other associated terminal equipment which originates an activation of an xDSL service;
answering station—the DTE, DCE and other associated terminal equipment which answers a call placed on the PSTN (GSTN);
carrier set—a set of one or more frequencies associated with a PSD mask of a particular xDSL Recommendation;
CAT3—cabling and cabling components designed and tested to transmit cleanly to 16 MHz of communications. Used for voice and data/LAN traffic to 10 megabits per second;
CAT5—cabling and cabling components designed and tested to transmit cleanly to 100 MHz of communications;
communication method—form of communication sometimes referred to as modems, modulations, line codes, etc.;
downstream—direction of transmission from the xTU-C to the xTU-R,
Galf—an octet having the value 8116; i.e., the ones complement of an HDLC flag;
initiating signal—signal which initiates a startup procedure;
initiating station—DTE, DCE and other associated terminal equipment which initiates a startup procedure;
invalid frame—frame that has fewer than four octets between flags, excluding transparency octets;
message—framed information conveyed via modulated transmission;
metallic local loop—communication channel 5, the metallic wires that form the local loop to the customer premise;
responding signal—signal sent in response to an initiating signal;
responding station—station that responds to initiation of a communication transaction from the remote station;
session—active communications connection, measured from beginning to end, between computers or applications over a network;
signal—information conveyed via tone based transmission;
signaling family—group of carrier sets which are integral multiples of a given carrier spacing frequency;
splitter—combination of a high pass filter and a low pass filter designed to split a metallic local loop into two bands of operation;
telephony mode—operational mode in which voice or other audio (rather than modulated information-bearing messages) is selected as the method of communication;
transaction—sequence of messages, ending with either a positive acknowledgment [ACK(1)], a negative acknowledgment (NAK), or a time-out;
terminal—station; and
upstream: The direction of transmission from the xTU-R to the xTUC.
Abbreviations
The following abbreviations are used throughout the detailed discussion:
ACK—Acknowledge Message;
ADSL—Asymmetric Digital Subscriber Line;
CCITT—International Telegraph and Telephone Consultative Committee;
CDSL—Consumer Digital Subscriber Line;
DSL—Digital Subscriber Line;
FSK—Frequency Shift Keying;
GSTN—General Switched Telephone Network (same as PSTN);
HDSL—High bit rate Digital Subscriber Line;
HSTU-C—handshaking portion of the xDSL central terminal unit (xTU);
HSTU-R—handshaking portion of the xDSL remote terminal unit (xTU-R).
ISO—International Organization for Standardization;
ITU-T—International Telecommunication Union—Telecommunication Standardization Sector;
NAK—Negative Acknowledge Message;
NTU—Network Termination Unit (Customer premise end);
PBO—Power Back Off,
PME—Power Management Exchange
PMM—Power Measurement Modulation;
PMMS—Power Measurement Modulation Session;
POTS—Plain Old Telephone Service
PSD—Power Spectral Density;
PSTN—Public Switched Telephone Network;
RADSL—Rate Adaptive DSL;
VDSL—Very high speed Digital Subscriber Line;
xDSL—any of the various types of Digital Subscriber Lines (DSL);
xTU-C—central terminal unit of an xDSL; and
xTU-R—remote terminal unit of an xDSL.
1. Field of the Invention
The present invention is directed to a high speed communications device, such as, for example, but not limited to, a modem, a cable modem, a xDSL modem, a satellite communication system, a point-to-point wired or wireless communication system, which includes a handshaking or initialing protocol, and in particular, to an apparatus and method that provides means to robustly select measurement procedures and robustly report the results of such measurement procedures.
2. Discussion of Background and Other Information
One of the important functionalities of the various xDSL schemes is to accurately control the amount of transmit power used on a specific xDSL line. Since each local loop used for xDSL has unique parameters, such as, for example, attenuation, interference, crosstalk, etc, it is desirable to accurately measure those parameters before blindly transmitting large amounts of power into the loop. Heretofore, each xDSL scheme has used it's own proprietary style of power measurement and control, with varying degrees of measurement and control.
Additionally, the power control measurement procedures of the prior art were typically used after the xDSL modulation had started, with large amounts of power already being transmitted.
Accordingly, there is a need for an apparatus and method that provides means to robustly select measurement procedures and robustly report the results of such measurement procedures, so as to minimize the amount of transmission power used to transmit data.
The ITU-T has published recommended methods for initiating data communication over voice band channels. The following three Recommendations have been produced, the subject matter of which is expressly incorporated herein by reference in their entirety:                1) Recommendation V.8, entitled “Procedures For Starting Sessions Of Data Transmission Over The General Switched Telephone Network”, published in September, 1994;        2) Recommendation V.8bis, entitled “Procedures For The Identification And Selection Of Common Modes Of Operation Between Data Circuit-Terminating Equipments (DCEs) And Between Data Terminal Equipments (DTEs) Over The General Switched Telephone Network”, published in August, 1996; and        3) Recommendation G.994.1, entitled “Handshake Procedures For Digital Subscriber Line (DSL) Transceivers”, published in June 1999.It is noted that document (3) is the final version of Temporary Document MA-006 that was published in March, 1999.        